S.chand class 6 Mathematics Chapter 14 Exercise 14A

 Exercise 14A

Question 1

1. Add:

(i) $x, 5 x, 2 x, 3 x$

(ii) $5 n, 7 n, 4 n, 3 n$

(iii) $5 b^{2},-3 b^{2}$,

(iv) $2 x,-7 x, 4 x,-x$

(v) $-x_{1},-x,-x$

(vi) $-2 a x^{4} y^{2},-9 a x^{4} y^{2}$

(vii) $6 a^{4} b^{2} x^{2},-6 a^{4} b^{2} x^{2}$

(viii) $3(a+b), 6(a+b)$

Question 2

Simplify the following.

(i) $5 b^{2}+3 b^{2}-8 b^{2}$

(ii) $9 x^{3}-10 x^{3}+8 x^{3}$

(iii) $4 m+2 m-m+2 m-2 m$

Question 3

(i) $\begin{array}{r}x+5 y \\3 x+y \\\hline$\end{array}

(ii) $\begin{aligned}&4 m+6 n \\&5 m+2 n \\&\hline \end{aligned}$

(iii) $\begin{array}{r}p+q\\3p+4 q\\ \hline$

(iv) $\begin{array}{r} -6x-2 \\ -x-5 \\ \hline\end{array}

(v) $\begin{array}{r} x^{2}+2\\-6 x^{2}+3$\\ \hline \end{array}

(vi) $\begin{aligned}&-c^{2}+7 c \\ &-4 c^{2}+8 c \\&\hline \end{aligned}$

(vii) $\begin{aligned}&3 a b-9 x y \\&7 a b+4 x y \\ &\hline \end{aligned}$

(viii) $\begin{aligned}&2 x^{2}-5 x \\ &9 x^{2}+2 x \\ &\hline \end{aligned}$

Question 4

Add the following.

(i) $\begin{aligned} &x^{2}+2 x-7 \\&x^{2}-5 x+3 \\ &\hline \end{aligned}$

(ii) $\begin{aligned} &5 a^{2}-2 a b-9 b^{2} \\ &-a^{2}+4 a b-b^{2} \\ &\hline \end{aligned}$

(iii) $\begin{array}{r} x^{2}-3 x+4 \\ 4 x^{2}-2 x+7 \\ -x^{2}+5 x-2 \\ \hline \end{array}$

Question 5

(i) $5 x^{2}+5 x-6$ and $4 x^{2}-x+8$

(ii) $3 y^{2}-4 y+5,2 y^{2}-7 y-1$, and $y^{2}-3 y-5$

Question 6

Simplify:

(i) $(2 x-y)+(2 y-3 x)+(3 y-x)$

(ii) $3 y^{2}-6-2 y+y^{2}-3 y+7-y^{2}-4 y-y^{2}+5$

Multiple Choice Questions (MCQ)

Tick (✔) the correct option.

7.If $P=2 a-5 b-7 c, Q=9 b-6 a-10 c$ and $R=17 c-4 b+4 a$, then $P+Q+R$ equals

(a) $15 a-9 b$

(b) $-34 c$

(c) 0

(d) $-12 a-10 b-7 c$